The present invention relates to a device for the ventilation of a fuel tank, and particularly for a motor vehicle, which in the interior of the tank is comprised of ventilation pipes, which run in a transverse direction to the vehicle, and whose inlet ports are disposed adjacent to opposite, vertical boundary walls of the fuel tank.
It has been proposed in another, conventional device of the aforementioned type German Auslegeschrift 2,045,004 that a duct section of the ventilation pipe running along the upper tank wall be provided with a bend on both its opposite ends which connect to pipe sections which point toward opposite boundary walls, and whose free ends have inlet ports. In the center area, the duct section is connected to an exit pipe penetrating the upper tank wall and running approximately perpendicular to the duct section. However, a disadvantage of this proposed arrangement resides in the fact that two bending processes of different bending radii are required for the production of the ventilation pipe necessitating the use of expensive tools. Furthermore, for the connection of the upper duct section to the exit pipe, time and cost intensive drilling and soldering processes must be performed. A further disadvantage resides in the fact that the bends cause the overall height to be relatively large, and that the two ventilation ducts are arranged at different heights of the fuel tank. This impairs optimum filling of the fuel tank.
A principle object underlying the present invention, therefore, is to create a device for the ventilation of a fuel tank, which, besides functioning well, is simple to produce and exhibits a small overall height.
This object is attained, according to a preferred embodiment of the present invention, by the use of ventilation pipes having different diameters, a pipe of smaller diameter having forked sections and being surrounded by a second pipe of larger diameter, in such a manner that free ends of the pipes provide intake ports at opposite lateral sides of the tank.
The primary advantages attained by the present invention reside in the fact that the interlocking of the two ventilation pipes makes it possible to use components that are simple to produce and, at the same time, assures good functioning. Furthermore, the device has a low overall height, and the connection of the pipe section with the exit pipe is achieved in a simple way.
These and further objects, features and advantages of the present invention will become more obvious from the following description when taken in connection with the accompanying drawings which show, for purposes of illustration only, several embodiments in accordance with the present invention.